Bayonet closure with gasket compression limiting means



April 1959 w. M. TERRY, JR., ETAL 2,883,083 v BAYONET CLOSURE WITHGASKET COMPRESSION LIMITING MEANS Filed Nov. 50. 1956 I II Iwuummmuummnunmmlll United States Patent BAYONET CLOSURE WITH GASKET COM-PRESSION LIMITING MEANS William M. Terry, Jr., and Nicholas J. Georges,Pittsburgh, Pa., assignors to Allis-Chalmers Manufacturing Company,Milwaukee, Wis.

Application November 30, 1956, Serial No. 625,528

2 Claims. (Cl. 220-40) This invention relates to tanks or receptaclesand more particularly to a new and improved means for removably clampingand sealing a cover to a transformer tank.

The clamping and sealing of a cover to a receptacle such as atransformer tank involves the application of compression forces on aresilient gasket between the cover and tank to obtain an effective fluidtight joint therebetween.

Heretofore, the practice in clamping a cover to a transformer tankinvolved the use of external evenly distributed bolts around theperiphery of the cover. This type of clamping device is difiicult topaint evenly around the clamp elements and provides rust gatheringpockets around the periphery of the tank. Thus, it is deemed importantto keep the clamping means free from the weathering elements. Further,in order to provide a good seal between the removable cover and thetransformer tank, the compression forces between the cover and the tankshould be controlled.

Therefore, in accordance with the present invention a new and improvedtransformer cover clamping structure is provided. This structurecomprises a plurality of inclined notched slides which are evenly spacedaround the inner surface of the cover and a plurality of projectionssuch as pins mounted on the tank, one arranged to engage each of thenotched surfaces during a clamping operation. The pins move over theslides until the pins are engaged in the notches thereby obtaining apredetermined sealing compression on the gasket between the cover andtank.

It is, therefore, one object of the present invention to provide a newand improved transformer cover clamping structure which will effectivelyresist weathering.

Another object of the invention is to provide a new and improvedtransformer cover clamping structure which will substantially enclosethe sealing gasket and subject it to a predetermined compression force.

A further object of this invention is to provide a new and improvedtransformer cover clamping structure which can be easily operated toengage or disengage the cover from the tank structure.

Objects and advantages other than those set forth above will be apparentfrom the following description when read in connection with theaccompanying drawings, in which:

Fig. l is an isometric view of an assembled distribution transformertank and cover with a cover adjusting bolting structure;

Fig. 2 is an enlarged isometric partial cut away view of a portion ofthe assembled distribution transformer tank and cover illustrating theinvention;

Fig. 3 is an enlarged axial cross sectional view of a portion of thetransformer cover and tank shown in Figs. 1 and 2 in sealing engagement;and

Fig. 4 is a cross sectional view of Fig. 3 on line IVIV.

Referring more particularly to the drawing by characters of reference,Figs. 1-4 illustrate a transformer comprising two relatively joiningmembers which are a 2,883,083 Patented Apr. 21, 1959 cylindricalreceptacle or tank 11 and a circular top or cover 12, a resilient gasket13 of suitable material such as synthetic rubber between the cover andtank, and a plurality of sealing or clamping means or compressioncomponents 14. The cover and tank are held in a clamping position by adisengageable fastening means 15 mounted along the periphery of themembers. Although the drawing shows the invention incorporated on atrans former tank, nevertheless, it is intended that the invention beused on any receptacle utilizing a cover.

There are particular advantages in the illustrated construction of thetank and cover. For example, it is desirable that the gasket material beprotected from exposure to the atmosphere which would cause aging anddeterioration of the gasket material. Likewise, it is desirable that thegasket material be protected from contact with the liquid inside of thetank, as the illustrated tank may have placed therein insulating liquidand an electrical apparatus.

The enlarged view of Fig. 3 clearly shows the tank and cover structure.The upper part of tank 11 is provided with a flange which is spaced fromupper edge 16 of the tank wall 11. The flange may be formed by inwardlyor outwardly extending the wall of the tank to provide a continuous stepshaped cross sectional flange as part of the tank. Upper surface 18 ofthe flange is flat, providing a flat seat for the gasket 13. Rim or lip17 of the wall of the tank extends upwardly from the inner edge of theflange, whereby the rim of the tank serves as a positioning andretaining means for the gasket which can be slipped over the rim ontothe fiat upper surface of the flange.

The central portion of the cover is preferably dome shaped and has adepending edge which has a three section step shaped portion and adownward outwardly flared portion or flange. The first section 19 isturned downwardly from the domed central portion of the cover so thatthere is an angle of slightly more than ninety degrees therebetween. Theintermediate section 20 is turned outwardly from the bottom of the firstsection with an angle of ninety degrees between the first section andthe horizontally extending intermediate section, and the third section21 is turned vertically downwardly from the outer edge of theintermediate section. The flared portion has a first section 22extending outwardly from the bottom of the third section of the stepshaped portion at an angle of approximately one hundred sixty degrees,

and a second section 23 turned vertically downward from the bottom ofthe first section of the flared portion.

Gasket 13 is compressed between two flat surfaces, one being the uppersurface 18 of the flange on the tank and the other being the flatsurface 20 of the depending edge portion of the cover 12, whereby theforce of compression on the gasket is distributed over the entire upperand lower surface of the gasket.

The step shaped portion of the depending edge of cover 12 cooperateswith the flange and with the upwardly extending rim 17 of the tank toenclose the gasket. The gasket is covered on top and bottom by the flatsurface 20 of the cover and by the flat upper surface 18 of the tank,respectively, and the gasket is enclosed on its inner and outer edges orsides by the lip or rim 17 of the tank and the vertical section 21 ofthe cover, respectively.

In addition to enclosing the inner and outer sides of the gasket, thedepending portion of the cover cooperates with the flange and the lip ofthe tank to provide a double guide means for properly placing the coveron the tank. The rim 17 of the tank is guided along the first oruppermost vertical section 19, of the cover as the cover is lowered ontothe tank, thereby providing an inside guide. An outside guide forplacing the cover on the tank is provided by the third or lower verticalsection 21 of the cover which slides along the vertical edge of theflange.

The spacing between the flared portion of cover 12 and the tank wall.provides space for containing the clamping means 14, thus keepingthemfree of the weathering elements. Within this space are mounted aplurality of projections 24 which are spaced radially outward around theouter periphery of the tank.

At spaced intervals around the inner periphery of the vertical section24 of the flared portion of cover 12 are attached notched arcuate slides25. One slide is provided for each projection 24-. Slides 2'5 areslightly inclined in the direction of rotation of cover 12' during aclamping operation and upon rotation of cover 12 clockwise, slides 25exert a force against the projections 24 causing cover 12 and tank 11 tocompress gasket 13, producing a sealing engagement.

Although Fig. 2 illustrates a slide extending around a portion of theinner periphery of the cover, each slide could also be arrangedto extendaround a portion of the outer periphery of the tank, thus mounting eachprojection around the inner periphery of the cover.

To prevent excessive compression which would be injurious to gasket 13 anotch or stop 26 is made on each slide 25 at a predetermined point alongits slope. These notches halt the movement of slides 25 on projections24 and indicate that a predetermined desired compression of gasket 13has been obtained. A gasket of material such as synthetic rubber shouldbe compressed to not more than one-third of its original thickness,otherwise its resiliency will be detrimentally affected.

An L-shaped stud 27 is welded to cover 12 and is threaded to accommodatethreaded members, for example, nut 39 and nut 31. A stud holder 28,which has a slot 29 for engaging the stud 27 is welded to the tank 11and extends radially outward.

In closing tank 12, cover 11 is first loosely placed in position byinserting stud 27 in slot 29. Nut 31 is then attached to stud 27, nut 30having been added previously to stud 27. Nut 30 is then turnedcounterclockwise causing the slides 25 to move under their respectiveprojections 24, thereby compressing gasket 13. This action continuesuntil the projections 24 snap into notches 26 of slides 25 at which timea specified compression force is applied to gasket 13 and the clampingoperation is completed. Nut 31 is then turned clockwise toward studholder 28 to lock cover 12 and receptacle 11 in this given relativeposition. Thus, disengageable means 15, mounted on the periphery of themembers 11 and 12,

relatively moves and holds the members in given relative positions.

Although only one embodiment of the present invention has beenillustrated and described, it will be apparent to those skilled in theart that various changes and modifications may be made therein withoutdeparting from the spirit of the invention or from the scope of theappended claims.

What is claimed is:

1. In combination, two relatively joining members comprising acylindrical receptacle provided with an opening therein and a cover forsaid opening, a downwardly extending flange integrally arranged on saidcover surrounding said opening, resilient gasket means mounted betweensaid members, means mounted on said members for causing said members tocompress said gasket means therebetween comprising two compressioncomponents, one of said components comprising a slide'having a camsurface substantially parallel to said flange, said cam surface having anotch at a predetermined position, the other of said componentscomprising a radially extending projection, one of said components beingmounted around the inner periphery of said flange and extending radiallyinwardly toward said receptacle, the other of said components beingmounted on the outer periphery of said receptacle and extending radiallyoutwardly to ward said flange, said components cooperating togetherwhereby movement of said projection along said cam surface efiects apredetermined amount of compression on said gasket means during joining'of said members, and means for relatively rotating said members and forbolding said members in a given position, said ineanscomprising an elbowshaped stud having a first leg externally mounted on said cover flangeand a threaded second leg positioned substantially parallel to saidcover and said flange, a stud holder externally mounted on saidreceptacle with a slot for closely containing said second leg of saidstud, and a pair of threaded members engaging said threaded second legand abutting opposite sides of said holder to adjust and secure saidstud in said holder.

2. In combination, two relatively joining members comprising acylindrical receptacle provided with an open ing therein and a cover forsaid opening, a downwardly extending continuous flange integrallyarranged on said cover and surrounding said opening, gasket materialarranged between said members, said flange having a plurality of arcuateslides substantially identically positioned around the inner peripheryof said flange and extending radially inwardly toward said receptacle,each of said slides being provided with a surface substantially parallelto said flange and inclining toward said cover, said surface havingtransverse elements perpendicular to said flange, each said surfacebeing provided with a stop at the end furthermost from the edge of saidflange, a plurality of projections mounted on the outer periphery ofsaid receptacle extending radially outwardly toward said flange, oneengaging each said surface during relative rotational movement of saidmembers, each of said projections and its cooperating surface effectinga predetermined compression force on said gasket material upon each ofsaid pnojections engaging said stop, and means for relatively rotatingsaid members and for holding said members in a given relative position,said means comprising a threaded stud externally mounted on saidflange,said stud having a threaded end portion substantially parallel to saidcover and said flange, a holder externally mounted on said receptacleforcontaining said stud and threaded members engaging said stud to adjustand secure said stud in said holder.

References Cited in the file of this patent UNITED STATES PATENTS1,341,592 Ruehle May 25, 1920 1,682,349 Reid Aug. 28, 1928 2,145,077Farr Jan. 24, 1939 2,179,136 Shoemaker Nov. 7, 1939 2,297,178 Tompkinset al Sept. 29, 1942 2,410,323 Wellman Oct. 29, 1946 FOREIGN PATENTS21,935 Switzerland July 28, 1900 733,195 France July 4, 1932 171,712Switzerland Dec. 1, 1934

